Honolulu Star-Advertiser © Susan Scott
Friday, September 26, 2008
A recent column I wrote discussed octopuses running around on beaches and climbing trees.
About that, NOAA fisheries biologist Don Kobayashi e-mailed me suggesting I check out “Words of the Lagoon,” a book by late marine biologist R.E. Johannes.
This collection of stories from Palauan fishermen is a wealth of information about traditional fishing and conservation practices. Some of the stories, though, are a little, well, fishy.
The chapter called “The Arboreal Octopus” recounts a tale fishermen told Johannes, whom they respected, about octopuses climbing mangrove trees. This wasn’t a one-time thing or hearsay. Quite a few older men claimed they’d seen this phenomenon several times in their lives.
The octopus, the fishers stated, climbs several feet above the water to the place where ferns grow from the tree’s trunk. There the octopus gives birth to dozens of babies, many of which are eaten by birds and crabs as they make their way to the water.
Except octopuses lay eggs. And unlike sea snakes, they do not incubate eggs inside their bodies and release baby octopuses.
Palauans aren’t the first people to believe octopuses occasionally visited the other side. The ancient Greeks thought octopuses walked on land. Greek poet Oppian wrote that these invertebrates also climb olive trees because (I love this) “they long for olives.”
Johannes reports credible accounts of octopuses in Palau’s waters briefly leaving the water to chase a crab on a beach, but never witnessed such an event.
As to another question that came up in a recent column, NOAA monk seal specialist, John Henderson, had a sound answer.
In an episode of “Survivor Fiji” a sea snake appeared to be giving birth through its mouth. Although that’s impossible, I didn’t know what the snake might be doing instead. But John did. He e-mailed:
“As a biologist and fan of ‘Survivor’ I saw the video and participated in something of an on-line discussion of what was actually depicted. What was shown was a sea snake regurgitating ‘something’ which was long, thin and banded. I’m pretty sure it was regurgitating a snake eel which it had previously eaten. I presume sea snakes, like lots of snakes, will regurgitate a recent meal if they’re disturbed, so I think that’s what was going on. It was obviously not giving birth (or shedding its skin … another popular online theory).”
John’s explanation makes sense. The distressed snake was throwing up its eel meal to lighten its body for a faster getaway.
An octopus giving birth in a tree, however, does not make sense. Even if octopuses did give live birth, what would be the advantage of a mother octopus entering the alien world of air breathers and then sending her offspring to the sea through an obstacle course of predators?
As fantastic as the accounts sounded, Johannes, a fine research biologist, never declared the octopus stories silly or false. He offered three hypotheses: It’s true octopuses have babies in trees; the fishers saw something they thought was octopuses having babies in trees; or the guys were pulling his leg.
Johannes didn’t believe any of those theories and never came up with another. The mystery of the “Survivor” snake may be solved, but the puzzle of tree-climbing octopuses goes on.